Many lighting applications utilize lighting fixtures that are configured to be suspended from ceilings or which may be recessed into a ceiling to provide illumination of an interior space. Manufacturers commonly utilize metal to form the housing and other structural components of such lighting fixtures. One drawback to the use of metal for lighting fixtures is that it is difficult and costly to provide the housing and structural components in complex shapes. For example, complex configurations may require forming portions of the fixture as separate pieces that are subsequently joined together, thereby adding to the manufacturing process and increasing weight. Moreover, metal structures create interference with wireless communication signals that are increasingly being used to control lighting and for other purposes. To address such interference, external antennas may be required, however, these are generally bulky, fragile during packaging and shipping, and may not provide an aesthetically pleasing appearance. Similarly, the use of metal in lighting fixtures presents limitations when it is desired to include sensors, such as motion sensors, into the fixtures. The incorporation of such sensors into lighting fixtures often requires additional parts and fasteners and disrupts the aesthetic appearance. Accordingly, there is a need for improved lighting fixtures that address these and other drawbacks of prior lighting fixtures.